Rose took to his Twitter account late on Wednesday and in a cryptic tweet said that “Tim Cook is the Donald Trump of the music industry.” Although Rose’s fans asked him what he might have meant by the comment, he’s been silent, leaving the Internet to speculate what it might—and might not—mean.

Rose is one of the best-known rock musicians in the world. He’s also used his platform on Twitter and elsewhere to share his political ideas. In a slew of tweets in recent months, Rose has made his distaste for Donald Trump and the president’s family known. On Jan. 4, for instance, Rose tweeted that “the White House is the current U.S. gold standard of what can be considered disgraceful.” Just last week, he said that the president’s daughter Ivanka Trump should not be “part of the White House administration.”

So, while Rose didn’t hurl a direct insult at Apple’s CEO, given his distaste for the president, he’s obviously not too happy with Cook.

While it’s hard to say exactly why Rose has an issue with Cook, Apple operates one of the most popular streaming and download services in the world in Apple Music and iTunes. Rose, a musician, could be referring in some way to those services. Guns N’ Roses music is available on Apple’s offerings.